Multiple Myeloma

Multiple myeloma Multiple myeloma (also plasma cell myeloma also known as MM, myeloma, plasma cell myeloma, or as Kahler's disease) is a progressive hematologic (blood) disease. It is a cancer of the plasma cell, an important part of the immune system that produces immunoglobulins (antibodies) to help fight infection and disease. The immune system is made up of several types of cells that work together to fight infections. Lymph cells (called lymphocytes) are the main type of cell in the adaptive immune system. There are 2 types of lymph cells: T cells and B cells. When B cells respond to an infection, they change into plasma cells. The plasma cells are found mainly in the bone marrow—the soft, inner part of some bones. The plasma cells make proteins called antibodies that attack and help kill germs. When plasma cells grow out of control, they can form a tumor, usually in the bone marrow. This type of tumor is called a myeloma, and if there are many tumors they are called multiple myeloma. If there is only one tumor, it is called solitary plasmacytoma. In many cases, this single tumor will go on to become multiple myeloma. Multiple myeloma is characterized by excessive numbers of abnormal plasma cells in the bone marrow and overproduction of intact monoclonal immunoglobulin (IgG, IgA, IgD, or IgE) or Bence-Jones protein (free monoclonal light chains). 1
Mechanism of developing malignant plasma cells: Normally, plasma cells make up a very small portion (less than 5%) of cells in the bone marrow. However, mostly multiple myeloma cell pathogenesis is based on bone marrow microenvironment. The subsets of bone marrow cell components including stromal cells, osteoclasts, and osteoblasts can modify growth advantage, survival and drug resistance of MM cells. Myeloma plasma cells, however, have specific adhesion molecules on their surface allowing them to target the bone marrow where they attach to structural cells called stromal cells. 2Once myeloma cells attach to